Subterranean clamping mechanism for submarine wells

ABSTRACT

The invention relates to a marine apparatus which includes a clamping device that is submergible beneath the water&#39;&#39;s surface to be aligned with, and to squeezably deform the upstanding well casing of an uncontrollably flowing well. The apparatus includes a clamping yoke having spaced apart arms which define an opening or slip for registering about the upstanding well casing. A pair of displaceable cross members extend from the termini of the arms to interlock with each other and to engage the well casing. A hydraulic cylinder carried on the yoke is adapted to urge the clamping device into contact with the casing whereby to deform and crush the latter against the interlocked cross members.

United States Patent 191 Pogonowski SUBTERRANEAN CLAMPING MECHANISM FORSUBMARINE WELLS Int. Cl. Fl6k 7/07, E2lb 33/06 Field of Search 166/55,55.1; 251/4-10, 1; 269/129, 156; 138/99; 294/64 BC, 83 R [5 6]References Cited UNITED STATES PATENTS 6/1941 Goode 294/83 R 3/1968Hunger.. 294/88 [451 June 26, 1973 Primary Examiner-Martin P. SchwadronAssistant Examiner-Richard Gerard Attarney--Thomas H. Whaley and Carl G.Ries 57 ABSTRACT The invention relates to a marine apparatus whichincludes a clamping device that is submergible beneath the waterssurface to be aligned with, and to squeezably deform the upstanding wellcasing of an uncontrollably flowing well. The apparatus includes aclamping yoke having spaced apart arms which define an opening or slipfor registering about the upstanding well casing. A pair of displaceablecross members extend from the termini of the arms to interlock with eachother and to engage the well casing. A hydraulic cylinder carried on theyoke is adapted to urge the clamping device into contact with the casingwhereby to deform and crush the latter against the interlocked crossmembers.

1 Claim, 6 Drawing Figures SUBTERRANEAN CLAMPING MECHANISM FOR SUBMARINEWELLS BACKGROUND OF THE INVENTION upstanding outer shell. The conductorfor crude oil or gas comprises a smaller flow line from about 6 to 10inches in diameter. Normally, said conductor is positioned within thecasing and extends downwardly to a gas pressure source of the crudeproduct.

Under normal operating conditions, upon completion of such a submergedoffshore well, the fluid carrying flow line is provided with a Christmastree arrangement to permit control of the fluids, both liquid and gas,which are drawn from the subterranean reservoir under pressure. ThisChristmas tree or valve arrangement connected to the flow line isadjustable to regulate flow from the reservoir and can be remotely ormanually actuated. Where however, unusual circumstances arise such thatthe well pressure exceeds a controllable level, or due to an equipmentfailure, the fluid, both liquid and gas, will gush in an uncontrolledstream from the reservoir.

This uncontrolled escape is not only an economic disaster, but carriesthe morepertinent stigma of being a potential mass pollutant of both thesurrounding water and the atmosphere. Further, ejection of raw wellgases into the atmosphere constitutes a tire hazard that can result inboth material damage and loss of life when such a well erupts and thegasesaccidentally ignite.

There presently exists a number of means whereby to stem thisuncontrolled fluid flow from a submerged well. Preferably, the well iscapped or plugged in such manner to either cut off the escaping fluids,or to permit the latter to be controllably regulated. The patent dangerto such an operation is however the inability to bring personnel such asdivers or submarine equipment to the immediate vicinity of the submergedWell head whereby to work on the latter.

Toward overcoming a situation as stated above, where a well isuncontrollably emitting quantities of petroleum fluids, the presentapparatus permits the submerged wellto be closed or choked off by aremote operation. Further, the operation is effectual, and minimizesthedanger to operating personnel. The device includes a controllablysubmerged body or yoke having movable parts which are actuated from thewaters surface, which device is lowered to the floor in of the well headto be closed.

The body includes at least two forwardly depending arms which define aslip therebetween for engaging or registering about a protruding wellhead casing. With the casing positioned between the respective arms,cross members, normally aligned with the arms, are pivotally displacedinto the slip area whereby to interlock and complete the encirclement ofthe casing. Thereafter, a remotely actuated clamping head exerts thevicinity external pressure against the casing wall and internal flowline respectively to deform and crush both of said members and therebystem the uncontrolled fluid flow.

DESCRIPTION OF THE DRAWINGS FIG. 1 represents a vertical elevation viewof a subterranean offshore well head which extends from the ocean floorand terminates at a point above the waters surface.

FIG. 2 is a top view taken along line 2-2 of FIG. 1,

shown with the clamping yoke fixedly engaged to the I well casing.

FIG. 3 is a front elevation view of the present apparatus.

FIG. 4 is similar to FIG. 2 showing the clamping device in a partiallyactuated condition.

FIG. 5 illustrates in cross section a casing and flow line subsequentlyto being deformed and FIG. 6 is a section view taken on line 6-6 of FIG.4.

Referring to FIG. 1, an offshore well of the type presently contemplatedis shown generally as consisting of an upstanding casing 10 formed of aseries of end connected steel tubular members, 30 to 48 inches indiameter. The elongated casing extends from a position near to, oradjacent the waters surface, downwardly to a desired depth in thesubstratum depending upon the consistenc-y and composition of thelatter. The elongated casing is fixed in place by a cement collar 14 orother suitable means as to be rigidly held in its imbedded position.Following normal construction of such a device, casing 10 surrounds acentrally positioned flow line 11 which extends downwardly, past thecasing lower end, and terminates in a liquid or oil reservoir.

Flow line 11 normally comprises threadably connected lengths of drillpipe varying from 6 to 10 inches in diameter. The pipe sections aresequentially connected as the depth of the well increases, and functionto carry petroleum fluids either gas or crude oil, from the pressurizedreservoir to the waters surface.

Flow line 1 1 is connected at its upper end to a Christmas treearrangement 12 presently illustrated by a plurality of valves extendingfrom the flow line upper end whereby to control and direct liquid andgases passing upwardly from the reservoir. Raw fluids leaving the wellare either separated, or passed directly by pipeline to a storage orrefinery facility.

It is appreciated that the instant arrangement of casing '10 and flowline 11, together with the above surface Christmas tree 12, isillustrative of a number of variations that could beapplied to anoffshore well. For example, in many instances the entire unit, includingflow line and Christmas tree, are completely submerged and remain at thefloor of the body of water whereby to minimize the possibility of saidequipment constituting a navigational hazard. In such an instance thewellhead is remotely operated to control fluid flow by use of any ofseveral known systemsJThe latter include pneumatic or electrical systemswhich connect to submerged actuators for the various valves. Further,such submerged well heads are communicated with a storage area for theproduced fluids by underwater flow lines which extend from the well headto a suitable gathering point either onshore or otherwise located.

Referring to FIG. 1, the casing clamping device 13 is illustrated in asubmerged condition at the floor of a body of water whereby to engage,and be positioned about casing 10 at a point adjacent the ocean floor.It should be noted that the clamping apparatus is normally disposed in agenerally horizontal disposition to most readily be aligned withupstanding well casing 10. Further, the disposition of the clampingdevice can be regulated not only by carriage means in sliding contactwith the ocean floor, but also by a suitable buoyancy system. In theinstance of the latter, and while not presently shown, the clampingdevice 13 can be controllably submerged to a desired distance from thewaters surface by use of a float arrangement adapted to suspend thesame.

Clamping device 13 comprises in essence a bifurcated body or yoke 16having a central portion 21 from which a pair of diametrally opposedarms 17 and 18 depend in a horizontal direction. Spaced apart arms 17and 18 define a slip area 19 therebetween of sufficient width, andadapted to register about the outside of well casing 10. Each armcomprises a structural member having a substantial cross section,particularly at the juncture with the body central section 21.

As shown in FIG. 2, the terminal end of each arm, 17 for example, isslotted along the inner side to receive a displaceable cross memberoperably connected thereto at vertically positioned hinge pin 22.Displaceable cross member 23 is pivotally connected at one end by way ofsaid pin 22 whereby to move in a horizontal plane. As shown in FIG. 2, aforwardly extending protrusion 24 depending from the arm 17 outer end,affords a lateral guide means whereby to align the respective arms withcasing as the clamping device is drawn to and about the casing.

Arms 17 and 18 as noted, are provided with displaceable, coacting crossmembers 23 and 26 respectively. Said cross members are adapted to becontrollably moved toward each other in a plane horizontal to, or withinthe common plane of the respective arms. Each cross member, such as 23,includes an elongated shank which extends from the hinge 22 andterminates at a remote contact face 27. The latter is provided with ahardened, anvil-like surface for engaging the casing 10 outer wall atsuch time as the cross members are engaged.

As shown in FIGS. 2 and 4, when the cross members are withdrawn they liesubstantially within the corresponding arm. Thus, open area 19 is freeof obstructions to register about casing 10. However, with said crossmembers in the extended or actuated position they are disposed outwardlyfrom the respective arms and are engaged approximately centrally of saidopen area 19.

To best withstand the axial force urged against the locked cross arms,the included angle therebetween is such as to distribute the resultingstress. Thus the casing deforming force will be transferred through therespective cross members and pivot pins, and thence into the arms 17 and18.

Referring to FIG. 6, to afford the respective cross members 23 and 26mutual strength when in the locked or engaged position, as shown in FIG.4, said cross members are provided with a slidably engaging lock jointat the remote face thereof. Said joint comprises in its simplest form atang 28 depending from cross member 23, which slidably registers withina corresponding groove 29 on cross member 26. Thus, and as shown in FIG.4, when the respective cross members are withdrawn outwardly from theirnormal position within their arms, they in effect, complete the closureabout casing 10. With the cross members so positioned, actuation of theclamping head 36 in a forward direction will serve to center casing 10with respect to the clamping surfaces.

Cross members 23 and 26 can be actuated to their engaged position asshown in FIGS. 4 and 6 by a number of mechanical means adapted to thepurpose. In the instant arrangement said means includes one or morehydraulically powered cylinders 31 and 32 which are pivotally positionedat one end to the upper and lower surfaces of arm 23. They are furtherconnected at the other end to cross member post 33. To bring the crossmembers into their withdrawn position, cylinders 31 and 32 are actuatedwhereby to position the member within the corresponding arm.

With the casing 10 held within the clamping device, partial actuation ofhydraulic cylinder 34 will center casing 10. Thus, the casing, as shownin FIG. 4, will be engaged by head 36. Further, advancing said head willthereafter bring the mating faces of locked cross members 23 and 26 intocontact with the casing outer wall.

Head 36 can be adjustable, or more preferably replaceable to properlyconform to the size of a particular well casing being deformed. Asshown, head 36 is provided with a curved contacting face to properlyengage a relatively extensive portion of the casing periphery whereby toachieve the desired crushing effect of both casing 10 and the innerpositioned flow line 11.

After being properly aligned, as casing 10 is subjected to increasedexternal pressure from opposed sides due to the progressive movement ofhydraulic head 36, the casing will assume the general disposition shownin FIG. 5. With further actuation of cylinder 34, outer casing 10 willbe deformed to the point that it crushes and substantially or completelycloses the inner positioned flow line 11. Thus, passage of both liquidand gas from the reservoir through the flow line 11, will be precluded.In such condition, the closed well can be readily worked on or furtherclosed by application of a cap or other device to further precludeuncontrolled fluid flow.

With the casing 10 closed off, the clamping device 13 is removed bywithdrawing clamping head 36 back into the hydraulic cylinder 34.Thereafter, the respective cross members 23 and 26 are withdrawn byactuation of the respective cylinders 31 and 32 such that the crossmembers fold into and adjacent to the arms 17 and 18. The entireclamping device can then be withdrawn from the casing and returned tothe Waters surface.

To facilitate movement along the ocean floor, and as shown in FIG. 1,clamping unit 13 is carried on a carriage 37 or similar propellableunit. The latter in one form, comprises a skid device from which theclamping unit is supported. A plurality of intermediate connectingmembers 38 and 39 are fixed, or telescopically adjustable to raise theclamping device a sufficient height beyond the ocean floor to permit theskid to be towed along said floor in a manner as to readily engagecasing 10.

Toward facilitating positioning of the clamping device about casing 10,each arm 17 and 18 is provided with a curved rubbing surface, onprotrusion 24, and with means to connect to a towing cable. The towingcables, as a matter of convenience can be connected to the skid orcarriage 37. In either instance, the inner surface of the clampingdevice is so arranged with respect to the cables that when the latterare towed by a floating vessel at the waters surface, the clampingdevice will tend to position itself about the casing.

Obviously many modifications and variations of the invention, ashereinafter set forth, may be made without departing from the spirit andscope thereof, and therefore, only such limitations should be imposed asare indicated in the appended claims.

I claim:

1. A marine apparatus for deforming a subterranean flow linecommunicated with a pressurized fluid source and carrying anuncontrolled flow of said fluid therefrom, which apparatus comprises;

a. a yoke having a pair of spaced apart parallel arms dependingtherefrom, and defining a slip area therebetween,

b. said arms forming an opening at the remote ends thereof to receivesaid flow line,

0. means for controllably positioning said yoke at an under waterlocation and in engagement with said subterranean flow line, whereby todispose the latter within said slip area,

d. an elongated beam removably extending from said respective arms andtraversing said slip area, said beam comprising discrete cross memberspivotally connected at one end to the respective arms, and beingpivotally displaceable between a withdrawn position adjacent to saidrespective arms, and an extended position within said slip area wherebyto engage the other of said cross members, and locking means on saidrespective cross members at the remote end from said pivot point wherebyto releasably engage a corresponding cross member end.

1. A marine apparatus for deforming a subterranean flow linecommunicated with a pressurized fluid source and carrying anuncontrolled flow of said fluid therefrom, which apparatus comprises; a.a yoke having a pair of spaced apart parallel arms depending therefrom,and defining a slip area therebetween, b. said arms forming an openingat the remote ends thereof to receive said flow line, c. means forcontrollably positioning said yoke at an under water location and inengagement with said subterranean flow line, whereby to dispose thelatter within said slip area, d. an elongated beam removably extendingfrom said respective arms and traversing said slip area, said beamcomprising discrete cross members pivotally connected at one end to therespective arms, and being pivotally displaceable between a withdrawnposition adjacent to said respective arms, and an extended positionwithin said slip area whereby to engage the other of said cross members,and locking means on sAid respective cross members at the remote endfrom said pivot point whereby to releasably engage a corresponding crossmember end.